Measurements of Dynamic Effects in FNAL 11-T Nb 3 Sn Dipole Models

Fermilab, in collaboration with CERN, has developed a double-aperture 11-T Nb 3 Sn dipole suitable for the high-luminosity LHC upgrade. During 2012–2014, a 2-m-long single-aperture dipole demonstrator and three 1-m-long single-aperture dipole models were fabricated by FNAL and tested at its Vertical Magnet Test Facility. Collared coils from two of the 1-m-long models were then used to assemble the first double-aperture dipole demonstrator. This magnet had extensive testing in 2015–2016, including quench performance, quench protection, and field quality studies. This paper reports the results of measurements of dynamic effects in the single-aperture and double-aperture 11-T Nb 3 Sn dipoles and compares them with similar measurements in previous NbTi magnets.